Well yeah, at that point you're comparing apples to oranges. It wouldn't be fair to compare headphones to speakers at all, especially in monitoring situations.
There is a unique exception to that rule, which I have experienced a demo of and handily nominate as
the most accurate headphone system ever devised. For most practical purposes it is as accurate as the speaker system to which it is calibrated, excepting the tactile low bass sensation region-
the Smyth Realiser. It is a system which includes a complex DSP box and Stax electrostatic ‘phones, although other ‘phones can be used with it. It requires an relatively extensive calibration procedure in the monitoring room to be emulated using microphones placed in the user’s ear canals. It also corrects for non-linearities in the phones themselves and the interface between them and your ears. The emulation is specific to each room and to each individual, but multiple emulations and user profiles can be stored and retrieved.
If it was priced more affordably I would most certainly own it, book an hour in a several different quality mastering facilities and run personal calibrations there as well as though my own system at home and a few other references such a couple mediocre systems and a few car stereos. I could then switch between all those virtual monitoring rooms while working anywhere that was quiet enough.
However, that system isn’t within the budget of most here including myself, so back on planet reality I use Sennheiser HD650s and agree with what others have said about the Senns in general. I can get pretty close doing a mix on them, but am never comfortable until listening on my speaker system.. and ideally several others. I’d like to give the Audeze cans a listen sometime, as well as the HD800.
Close coupled ear response varies from person to person*, so specific models which work best for others may not work best for you, however the recommendations here are all good candidates. The AKG k701s which work well for Noah, don’t play nicely at all with my personal ear canal resonance for example, but they are good ‘phones and others love them. You probably know this, but generally open backed phones are more accurate, though far less isolating than closed back phones, and most of what has been suggested here are open backed, except the Sonys.
*That large variability in transfer response between headphones and ears is one reason why the calibration process used by the Smyth system makes it the most accurate- it makes a separate measurement and modification for the transfer response between the headphones and your ears as well as the transfer response between the room being emulated and your ears. That means it is not just emulating your ears listening from the sweet spot in a specific speaker/room combination, but also correcting the headphones themselves and your individual response to them, within the limits of the system's capabilities.